Improvement in fruit-jars



UNITED STATES PATENT FFICE.

JOHN L. MASON, OF NEW BRUNSWICK, NEW JERSEY.

IMPROVEMENT IN FRUIT-JARS.

Specification forming part of Letters Patent No. 137.461, dated Apxil l, 1873 applicafion led March 6, I873.

To all whom it may concern:

Beit known that I, JOHN L. MASON, of New Brunswick, in the county of Middlesex and State of New Jersey, have invented a new and useful Improvement in Fruit-Jars; and I do hereby declare the following to be a full, clear, and exact description thereof, which will enable those skilled inthe art to make and use the same, reference being had to the accompanying drawing forming part ot' this specification, in which drawing- Figure l represents a side view of my invention. Fig. 2 is a vertical central section of the same.

Similar letters indicate corresponding parts.

This invention consists in the arrangement of square shoulders at both ends of the screwthread on the neck of a fruit-jar, so as to get full threads to start with both in turning the screw-cap down and up, and thereby said cap is effectually prevented from running over the thread; also, in a rubber gasket supported on a shoulder below the top of the neck of a fruitjar, and projecting above said top so as to form a true bearing-surface for the cover entirely independent of and above the top edge of the jar, said rubber gasket being used in combination with a dat cover, and producing with such cover a tight joint without the necessity of grinding off the top edge of the jar.

In the drawing, the letter A designates a fruit-jar, which is made of glass or other suitable material, and on the neck of which is formed a screw-thread, B, to receive the cap O. This screw-thread is provided with square shoulders a a at both ends, which may be produced by forming in the neck a groove, b, running transversely across the screw-threads, as

shown in Fig. l, while those parts of the neck on the sides of said groove opposite to the shoulders a a are left smooth; or said shoulders a c may be formed in any desirable manner.

By forming such square shoulders at the endsof the thread B, I obtain full threads for the screw-cap to start with, both in turning the cap in and in turning it out, and the cap is not liable to run over the threads.

The neck of my jar is provided with a shoulder, c, which is situated below the top edge of the jar, and which, being made in the mold, is true with the screw-thread, B. On this shoulder is placed the gasket d, which is made of India rubber or other suitable material, with its upper and lower surface perfectly parallel, and of such a width that when said gasket is placed on the shoulder c its upperedge will project above the top edge ofthe jar and form a bearing-surface for the cover D, which is true with the screw-thread B, and which is entirely independent of the top edge of the jar.

The cover D is Hat, and, as near as possible, ot' uniform thickness; and after the same has been placed upon the gasket d the screw-cap is applied, and the cover is rmly and evenly depressed upon the gasket.

By lthese means I am enabled to produce a tight joint between the jiat cover D and the jar A-without the necessity of grinding 0E the top edge of the jar, the bearing-surface of the cover being entirely independent of said top edge.

What I claim as new, and desire to secure by Letters Patent, is-

l. The square shoulders c o on the ends of l the screw-threads B B, formed by the transverse groove b on the neck of the jar, in combination with the screw-cap C, substantially as described.

2. The flat cover D, in combination with the gasket d, arranged on the shoulder c below the top edge of the jar, the flat cover being depressed on the gasket by the cap O, substantially as described.

JOHN L. MASON.

Witnesses E. F. KASTENHUBER, W. HAUFF. 

